Aqueous alkaline cleaning compositions and methods of their use

ABSTRACT

Aqueous alkaline composition free from organic solvents and metal ion-free silicates, the said compositions comprising (A) a thioamino acid having at least one primary amino group and at least one mercapto group, (B) a quaternary ammonium hydroxide, (C) a chelating and/or corrosion inhibiting agent selected from the group consisting of aliphatic and cycloaliphatic amines having at least two primary amino groups, and aliphatic and cycloaliphatic amines having at least one hydroxy group, (D) a nonionic surfactant selected from the group of acetylenic alcohols, alkyloxylated acetylenic alcohols and alkyloxylated sorbitan monocarboxylic acid mono esters; the use of the alkaline composition for the processing of substrates useful for fabricating electrical and optical devices; and a method for processing substrates useful for fabricating electrical and optical devices making use of the said aqueous alkaline composition.

FIELD OF THE INVENTION

The present invention relates to new aqueous alkaline cleaningcompositions for processing substrates useful for fabricating electricaland optical devices, in particular electrical devices, includingcompositions useful for surface preparation, pre-plaiting cleaning,post-etch cleaning and post-chemical mechanical polishing cleaning.

Moreover, the present invention relates to new methods for processingsubstrates useful for fabricating electrical and optical devices, inparticular electrical devices, including new methods for surfacepreparation, pre-plaiting cleaning, post-etch cleaning and post-chemicalpolishing cleaning, which new methods make use of the new aqueousalkaline cleaning compositions.

CITED DOCUMENTS

The documents cited in the present application are incorporated byreference in their entirety.

DESCRIPTION OF THE PRIOR ART

The fabrication of electrical devices, in particular, semiconductorintegrated circuits (ICs); liquid crystal panels; organicelectroluminescent panels; printed circuit boards; micro machines; DNAchips; micro plants and magnetic heads; preferably ICs with LSI(large-scale integration) or VLSI (very-large-scale integration); aswell as optical devices, in particular, optical glasses such asphoto-masks, lenses and prisms; inorganic electro-conductive films suchas indium tin oxide (ITO); optical integrated circuits; opticalswitching elements; optical waveguides; optical monocrystals such as theend faces of optical fibers and scintillators; solid laser monocrystals;sapphire substrates for blue laser

LEDs; semiconductor monocrystals; and glass substrates for magneticdisks; requires high precision methods which involve inter alia surfacepreparation, pre-plaiting cleaning, post-etch cleaning and/orpost-chemical polishing cleaning steps using high-purity cleaningcompositions.

Particular care has to be taken in the fabrication of ICs with LSI orVLSI. The semiconductor wafers used for this purpose include asemiconductor substrate such as silicon, into which regions arepatterned for the deposition of different materials having electricallyinsulative, conductive or semiconductive properties.

In order to obtain the correct patterning, excess material used informing the various layers on the substrates must be removed. Further,to fabricate functional and reliable ICs, it is important to have flator planar semiconductor wafer surfaces. Thus, it is necessary to removeand/or polish certain surfaces of a semiconductor wafers during thefabrication of the ICs before carrying out the next process steps.

Chemical Mechanical Polishing or Planarization (CMP) is a process inwhich material is removed from a substrate surface, as for example, thesurface of a semiconductor wafer, and the surface is polished(planarized) by coupling a physical process such as abrasion with achemical process such as oxidation or chelation. In its most rudimentaryform, CMP involves applying a slurry, i.e. a suspension of an abrasiveand an active chemistry, to a polishing pad that buffs the surface of asemiconductor wafer to achieve the removal, planarization and polishing.It is not desirable for the removal or polishing to be comprised ofpurely physical or purely chemical action, but rather the synergisticcombination of both in order to achieve a fast uniform removal. In thefabrication of ICs, the CMP slurry should also be able to preferentiallyremove films that comprise complex layers of metals and other materialsso that highly planar surfaces can be produced for subsequentphotolithography, patterning, etching and thin-film processing.

Nowadays, copper is increasingly used for metal interconnects in ICs. Inthe copper damascene or dual damascene process commonly used for themetallization of circuitry in the semiconductor fabrication, the layersthat must be removed and planarized include copper layers having athickness of about 1-1.5 μm and copper seed layers having a thickness ofabout 0.05-0.15 μm. These copper layers are separated from the low-k andultra low-k dielectric material by a layer of barrier material,typically about 5 to 30 nm thick, which prevents diffusion of copperinto the low-k or ultra low-k dielectric material. The key to obtaininggood uniformity across the wafer surface after polishing is to use a CMPslurry that has the correct removal selectivities for each material.

The foregoing processing operations involving wafer substrate surfacepreparation, deposition, plating, etching and chemical mechanicalpolishing variously require cleaning operations to ensure that the ICsare free from contaminants that would otherwise deleteriously affect thefunction of the ICs, or even render them useless for their intendedfunctions.

One particularly grave issue are the residues that are left on thesubstrates following CMP processing. Such residues include CMP materialand corrosion inhibitor compounds such as benzotriazole (BTA). Thus, thecopper ion concentration can exceed the maximum solubility of thecopper-inhibitor complexes during CMP. Therefore, the copper-inhibitorcomplexes can precipitate from solution and can coagulate into a surfaceresidue. Moreover, these residues can stick to the surface of thepolishing pad and accumulate to eventually filling the grooves in thepolishing pad. Additionally, abrasive particles and chemicals containedin the CMP slurries as well as reaction by-products can be left behindon the wafer surface. Furthermore, the polishing of copper damascenestructures containing ultra low-k dielectric materials such ascarbon-doped oxides or organic films can generate carbon-rich particlesthat settle on to the wafer surface. Of course, all these residues canalso contaminate the processing tools employed in the process which comeinto contact with the CMP slurries. To make matters worse these ultralow-k dielectric materials as well as silicon carbide, silicon nitrideor silicon oxynitride CMP stop layers are very hydrophobic and hence aredifficult to clean with water-based cleaning solutions.

All these residues can cause a severe roughening of the coppermetallization, which has to be avoided since this causes a poorelectrical performance.

Another residue-producing process common to IC manufacturing involvesgasphase plasma etching to transfer the patterns of developedphotoresist coatings to the underlying layers, which may consist ofhardmask, interlevel dielectric and etch-stop layers. Post gasphaseplasma etch residues, which may include chemical elements present on andin the substrate and in the plasma gases, are typically deposited on theback end of the line (BEOL) structures and, if not removed, mayinterfere with the subsequent silicidation and contact formation.

In order to ameliorate these problems at least to a certain extent,aqueous alkaline cleaning and stripping compositions containingquaternary ammonium hydroxides had been developed and were disclosed inthe prior art.

Thus, the American patent U.S. Pat. No. 6,465,403 B1 discloses aqueousalkaline compositions for stripping or cleaning semiconductor wafersubstrates which contain

-   -   bases such as quaternary ammonium hydroxides,    -   metal ion-free silicates such as quaternary ammonium silicates,        and    -   metal chelating agents        as the obligatory ingredients. The compositions may furthermore        contain    -   organic solvents, and    -   non-ionic, anionic, cationic and amphoteric surfactants.

The non-ionic surfactants can be selected from the group consisting ofacetylenic alcohols, ethoxylated acetylenic alcohols, fluorinatedalkyesters, fluorinated polyoxyethylene alkanols, aliphatic acid estersof polyhydric alcohols, polyoxyethylene monoalkyl ethers,polyoxyethylene diols, polyoxyethylene esters, siloxane type surfactantsand alkylene glycol monoalkyl ethers.

In particular, Example 29, column 47, line 10 to column 49, line 8 inconjunction with the Table 28 discloses the solution S8 which consistsof

-   -   de-ionized water,    -   tetramethylammonium silicate,    -   tetramethylammonium hydroxide,    -   trans-(1,2-cyclohexylenenitrilo)-tetraacetic acid, and    -   cysteine as a potential titanium residue removal enhancer.

However, the test results presented in the Table 28 show that cysteinehas no beneficial effect.

The American patent application US 2005/0181961 A1 and the Americanpatent U.S. Pat. No. 7,435,712 B2 disclose aqueous alkaline CMP cleaningcompositions containing

-   -   cleaning agents such as tetraalkylammonium hydroxide,    -   complexing agents such as cysteine or ethylenediamine and    -   corrosion-inhibiting compounds such as cysteine as the        obligatory ingredients. The compositions may furthermore contain        non-ionic, anionic, cationic or amphoteric surfactants or        mixtures thereof. However, the surfactants are not specified        nearer.

The American patent application US 2006/0166847 A1, page 5, paragraphs[0082] and

discloses the aqueous alkaline cleaning composition K containing interalia

-   -   ethanolamine,    -   tetramethylammonium hydroxide and    -   cysteine;        and the aqueous cleaning composition M containing inter alia    -   ethanolamine,    -   tetramethylammonium hydroxide and    -   ethylenediamine.

However, as can be taken from page 8, Table 1 in conjunction withparagraph [0161], both compositions exhibit only a poor cleaningefficiency. Moreover, according to page 12, Example 13, paragraph [0198]in conjunction with the FIG. 9, the said aqueous alkaline cleaningcompositions also cause a high roughness of the treated copper surfaces.

The prior art aqueous alkaline cleaning or stripping compositions aresusceptible to degradation when exposed to oxygen, which in turn resultsin darkening of the color of the compositions, with the result thatsensors associated with the fabrication process tools yield erroneousoutputs that can compromise the function and reliability of the tool.Additionally, such degradation involves the loss of cleaning and/orstripping power. This can become so extensive in the case of prolongedoxygen exposure that the cleaning or stripping composition has no longera significant efficacy.

The prior art discussed above does not offer any hints as to how theseproblems may be resolved. In particular, it appears that ingredientssuch as cysteine or ethylenediamine at best offer no advantages if theyare not altogether disadvantageous as demonstrated by the internationalpatent application WO 2006/081406 A1 or the American patent applicationUS 2006/0166847 A1 discussed above.

As regards cysteine, it is well known in the art that this compound iseasily oxidized (cf., for example, Shayne C. Gad, Handbook ofPharmaceutical Biotechnology, John Wiley and Sons, 2007, page 328).Moreover, traces of heavy metals in particular iron and copper candecompose cysteine (cf. Römpp Online 2009, “L-cysteine”). Consequently,one would even less so expect that aqueous alkaline cleaningcompositions could ameliorate the problems described above.

The international patent application WO 2005/093031 A1 discloses animproved acidic chemistry for post-CMP cleaning. The acidic cleaningsolution is in the neutral to low pH range and comprises a cleaningagent such as cysteine or salicylic acid and a corrosion-inhibitingcompound such as as cysteine. However, such acidic chemistry tends toattack metallic surfaces to a much greater extent, in particular in thepresence of complexing agents and oxygen. Therefore, the skilled artisancan derive nothing from the international patent application as to howhe could increase the undesirably low stability of the alkaline cleaningcompositions containing cysteine.

The prior international patent application PCT/EP2010/058422 filed onJun. 16, 2010 and claiming the priority of the U.S. provisional patentapplication Ser. No. 61/221,807 filed on 20 Jun. 30, 2009 describesaqueous alkaline cleaning compositions containing

-   (A) at least one thioamino acid having at least one primary amino    group and at least one mercapto group,-   (B) at least one quaternary ammonium hydroxide,-   (C) at least one chelating and/or corrosion inhibiting agent    selected from the group consisting of aliphatic and cycloaliphatic    amines having at least two primary amino groups, aliphatic and    cycloaliphatic amines having at least one hydroxy group, and    aromatic compounds having at least one acid group and at least one    hydroxy group, and-   (D) at least one organic solvent having wetting properties and a    melting point below 0° C. as the obligatory ingredients. The    compositions may furthermore contain functional additives (E) which    are different from the essential components (A), (B), (C) and (D)    and which can be selected from the group consisting of corrosion    inhibitors, bases, titanium residue removal enhancers, organic    solvents, alcohols having at least one mercapto group, complexing or    chelating agents, surfactants and metal free silicates as described    in the American patents U.S. Pat. No. 6,465,403 B1, column 7, line 1    to column 8, line 65; U.S. Pat. No. 6,200,947 B1, column 2, lines 29    to 40, U.S. Pat. No. 6,194,366 B1, column 3, lines 55 to 60, and    U.S. Pat. No. 6,492,308 B1, column 3, lines 1 to 9, and the American    patent application US 2005/0181961 A1, page 2, paragraph [0019].

OBJECTS OF THE INVENTION

It was an object of the present invention to provide novel aqueousalkaline cleaning compositions for processing substrates useful forfabricating electrical devices, in particular, semiconductor integratedcircuits (ICs); liquid crystal panels; organic electroluminescentpanels; printed circuit boards; micro machines; DNA chips, micro plantsand magnetic heads; more preferably ICs with LSI (large-scaleintegration) or VLSI (very-large-scale integration); as well as opticaldevices, in particular, optical glasses such as photo-masks, lenses andprisms; inorganic electro-conductive films such as indium tin oxide(ITO); optical integrated circuits; optical switching elements; opticalwaveguides;

optical monocrystals such as the end faces of optical fibers andscintillators; solid laser monocrystals; sapphire substrates for bluelaser LEDs; semiconductor monocrystals; and glass substrates formagnetic disks, which fabrication requires high precision methodsinvolving inter alia surface preparation, pre-plaiting cleaning,post-etch cleaning and/or post-CMP cleaning steps using high-puritycleaning compositions.

In particular, the novel aqueous alkaline cleaning compositions shouldno longer exhibit the disadvantages of the prior art compositions suchas too fast a discoloration, darkening and decomposition upon exposureto oxygen so that they can be easily prepared, stored, transported,handled and used even after a comparatively long storage without loss ofcleaning and/or stripping power and without causing erroneous outputs ofthe sensors associated with the fabrication process tools, which outputscan compromise the function and reliability of the tools.

The novel aqueous alkaline cleaning compositions ought to beparticularly well-suited for carrying out the above-mentioned cleaningsteps, in particular, the post-CMP cleaning of semiconductor wafersduring the fabrication of ICs with LSI or VLSI, in particular via thecopper damascene or dual damascene process.

The novel aqueous alkaline cleaning compositions ought to remove mostefficiently all kinds of residues and contaminants generated during thesubstrate surface preparation, deposition, plating, etching and CMP toensure that the substrates, in particular the ICs, are free fromresidues and contaminants that would otherwise deleteriously affect thefunctions of the electrical and optical devices, in particular the ICs,or render them even useless for their intended functions. In particular,they should prevent the roughening of the copper metallization indamascene structures.

Moreover, the novel aqueous alkaline cleaning compositions ought toremove most efficiently such residues and and contaminants not only fromthe substrates but also from the fabrication tools which are used in thevarious processes.

It was another object of the invention to provide novel methods forprocessing substrates useful for fabricating electrical devices, inparticular, semiconductor integrated circuits (ICs); liquid crystalpanels; organic electroluminescent panels; printed circuit boards; micromachines; DNA chips; micro plants and magnetic heads; more preferablyICs with LSI (large-scale integration) or VLSI (very-large-scaleintegration); as well as optical devices, in particular, optical glassessuch as photo-masks, lenses and prisms; inorganic electro-conductivefilms such as indium tin oxide (ITO); optical integrated circuits;optical switching elements; optical waveguides; optical monocrystalssuch as the end faces of optical fibers and scintillators; solid lasermonocrystals; sapphire substrates for blue laser LEDs; semiconductormonocrystals; and glass substrates for magnetic disks, which novelmethods make use of the novel aqueous alkaline cleaning compositions.

In particular, the novel methods for fabricating electrical and opticaldevices, in particular electrical devices, ought to involve surfacepreparation, pre-plaiting cleaning, post-etch cleaning and/or post-CMPcleaning steps, more particularly post-etch and/or post-CMP cleaningsteps, and, most particularly, post-CMP cleaning steps using the novelaqueous alkaline cleaning compositions.

The novel methods for fabricating electrical devices ought to beparticularly well-suited for the fabrication of ICs with LSI or VLSI,especially with the help of the copper damascene and dual damasceneprocess. Regarding the copper damascene and dual damascene process, thenovel methods ought to remove contaminants and residues such asparticles consisting of or containing copper, copper oxide,copper-inhibitor complexes, abrasives and carbon after the CMP step fromthe substrate surfaces, the polishing pads and other processing toolsmost efficiently without scratching, etching and roughening the coppersurfaces.

SUMMARY OF THE INVENTION

Accordingly, the novel aqueous alkaline cleaning compositions free fromorganic solvents and metal ion-free silicates were found, the saidcompositions comprising

(A) at least one thioamino acid having at least one primary amino groupand at least one mercapto group,

(B) at least one quaternary ammonium hydroxide,

(C) at least one chelating and/or corrosion inhibiting agent selectedfrom the group consisting of aliphatic and cycloaliphatic amines havingat least two primary amino groups, and aliphatic and cycloaliphaticamines having at least one hydroxy group,

(D) at least one nonionic surfactant selected from the group ofacetylenic alcohols, alkyloxylated acetylenic alcohols and alkyloxylatedsorbitan monocarboxylic acid mono esters.

Hereinafter the novel aqueous alkaline cleaning compositions arereferred to as the “compositions of the invention”.

Moreover, the novel methods for processing substrates useful forfabricating electrical and optical devices were found, the said methodsmaking use of at least one composition of the invention in at least oneprocess step.

Hereinafter the novel methods for processing substrates useful forfabricating electrical and optical devices are referred to as the“methods of the invention”.

Last but not least, the novel use of the composition of the inventionfor the processing of substrates useful for fabricating electrical andoptical devices has been found.

ADVANTAGES OF THE INVENTION

In view of the prior art discussed above, it was surprising and couldnot be expected by the skilled artisan that the objects underlying thepresent invention could be solved by the compositions and the methods ofthe invention.

It was particularly surprising that the compositions of the inventionwere excellently suited for processing substrates useful for fabricatingelectrical devices, in particular, semiconductor integrated circuits(ICs); liquid crystal panels; organic electroluminescent panels; printedcircuit boards; micro machines; DNA chips; micro plants and magneticheads; more preferably ICs with LSI (large-scale integration) or VLSI(very-large-scale integration); as well as optical devices, inparticular, optical glasses such as photo-masks, lenses and prisms;inorganic electro-conductive films such as indium tin oxide (ITO);optical integrated circuits; optical switching elements; opticalwaveguides; optical monocrystals such as the end faces of optical fibersand scintillators; solid laser monocrystals; sapphire substrates forblue laser LEDs; semiconductor monocrystals; and glass substrates formagnetic disks.

It was even more surprising that the compositions of the invention weremost excellently suited for high precision fabrication methods involvinginter alia surface preparation, pre-plaiting cleaning, post-etchcleaning and/or post-CMP cleaning steps.

The compositions of the invention themselves no longer exhibited thedisadvantages of the prior art compositions such as too fast adiscoloration, darkening and decomposition upon exposure to oxygen sothat they could be easily prepared, stored, transported, handled andused even after a comparatively long storage without loss of cleaningand/or stripping power and without causing erroneous outputs of thesensors associated with the fabrication processing tools, which outputscompromised the function and reliability of the processing tools.

The compositions of the invention were most particularly well-suited forcarrying out the above-mentioned cleaning steps, in particular, thepost-CMP cleaning of semiconductor wafers and the fabrication of ICswith LSI or VLSI, in particular by the copper damascene or dualdamascene process.

The compositions of the invention removed most efficiently all kinds ofresidues and contaminants generated during the substrate surfacepreparation, deposition, plating, etching and CMP and ensured that thesubstrates, in particular the ICs, were free from residues andcontaminants that would have otherwise deleteriously affected thefunctions of the electrical and optical devices, in particular the ICs,or would have rendered them even useless for their intended functions.In particular, they prevented the scratching, etching and roughening ofthe copper metallization in damascene structures.

Moreover, the compositions of the invention removed such residues andand contaminants most efficiently not only from the substrates but alsofrom processing tools used in the various fabrication processes.

It was most particularly surprising that the methods of the inventionwere most excellently suited for fabricating electrical devices, inparticular, semiconductor integrated circuits (ICs); liquid crystalpanels; organic electroluminescent panels; printed circuit boards; micromachines; DNA chips; micro plants and magnetic heads; more preferablyICs with LSI (large-scale integration) or VLSI (very-large-scaleintegration); as well as optical devices, in particular, optical glassessuch as photo-masks, lenses and prisms; inorganic electro-conductivefilms such as indium tin oxide (ITO); optical integrated circuits;optical switching elements; optical waveguides; optical monocrystalssuch as the end faces of optical fibers and scintillators; solid lasermonocrystals; sapphire substrates for blue laser LEDs; semiconductormonocrystals; and glass substrates for magnetic disks.

In particular, the methods of the invention were most excellently suitedfor the fabrication of electrical and optical devices, in particularelectrical devices, which fabrication involved surface preparation,pre-plaiting cleaning, post-etch cleaning and/or post-CMP cleaningsteps, more particularly post-etch and/or post-CMP cleaning steps, and,most particularly, post-CMP cleaning steps.

The methods of the invention were most particularly well-suited for thefabrication of ICs with LSI or VLSI, especially with the help of thecopper damascene and dual damascene process. Regarding the copperdamascene and dual damascene process, the methods of the inventionremoved contaminants and residues such as particles containing orconsisting of copper, copper oxide, copper-inhibitor complexes,abrasives and carbon after the CMP steps from the substrate surfaces,the polishing pads and other processing tools most efficiently withoutscratching, etching and roughening the copper surfaces.

DETAILED DESCRIPTION OF THE INVENTION

In its broadest aspect the present invention relates to the compositionsof the invention.

The compositions of the invention are aqueous alkaline cleaningcompositions for processing substrates useful for fabricating electricaland optical devices.

“Aqueous” means that the compositions of the invention contain water.The water content can vary broadly from composition to composition.

“Alkaline” means that the compositions of the invention have a pH in therange of from 8 to 14, preferably 9 to 13 and, most preferably, 8.5 to12.5.

The compositions of the invention comprise as the first essentialcomponent at least one, preferably one thioamino acid (A) having atleast one, preferably one primary amino group and at least one,preferably one mercapto group. The thioamino acid (A) may be ansynthetic or naturally occurring, preferably a naturally occurring aminoacid. More preferably, the thioamino acid (A) is an alpha-amino acid.Even more preferably, the mercapto group of the thioamino acid (A) is inthe gamma-position. Most preferably, the thioamino acid (A) is analpha-amino acid having the mercapto group in the gamma-position.

Most particularly preferably, the thioamino acid (A) has the generalformula I:HS—[—C(—R¹)(—R²)—]_(n)—C(—R³)(—NH₂)—COOH  (I).

In the general formula I the index n is an integer of 1 to 3, preferably1 or 2. Most preferably, n equals 1.

The residues R¹ and R² of the general formula I are selectedindependently from each other from the group consisting of

-   -   hydrogen atoms;    -   straight and branched, saturated and unsaturated, preferably        saturated, substituted and unsubstituted, preferably        unsubstituted aliphatic residues having 1 to 10 carbon atoms,        preferably alkyl residues, in particular methyl, ethyl, propyl,        isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl,        1-methyl butyl, 2-methyl butyl, 3-methyl butyl, 1-ethyl propyl,        1,2-dimethyl propyl, 2,2-dimethyl propyl, hexyl, heptyl, octyl,        iso-octyl, nonyl or decyl;    -   substituted and unsubstituted, preferably unsubstituted,        saturated and unsaturated, preferably saturated cycloalkyl        residues having 3 to 8 carbon atoms, in particular cyclopropyl,        cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and        residues derived from by bicyclo[2.2.1]cycloheptane or        norcarane;    -   substituted and unsubstituted, preferably unsubstituted,        saturated and unsaturated, preferably saturated alkylcycloalkyl        residues wherein the alkyl group is having from 1 to 4 carbon        atoms and the cycloalkyl group is having from 3 to 8 carbon        atoms, in particular residues derived from methyl-, ethyl-,        propyl-, isopropyl- or butyl-substituted cyclopropane,        cyclobutane or cyclohexane, pinane or bornane, which        alkylcycloalkyl residues may be linked to the basic structure of        the thioamino acid (A) of the general formula I via a carbon        atom of the alkyl group or via a carbon atom of the cycloalkyl        group;    -   substituted and unsubstituted, preferably unsubstituted aryl        residues having from 6 to 16 carbon atoms, in particular phenyl        or naphthyl or residues derived from anthracene or phenanthrene;    -   substituted and unsubstituted, preferably unsubstituted        alkylaryl residues wherein the alkyl group is having from 1 to 4        carbon atoms and the aryl group is having from 6 to 16 carbon        atoms, in particular methyl-, ethyl-, propyl-, isopropyl- or        butyl-substituted phenyl or naphthyl or residues derived from        methyl-, ethyl-, propyl-, isopropyl- or butyl-substituted        anthracene or phenanthrene which alkylaryl residues may be        linked to the basic structure of the thioamino acid (A) of the        general formula I via a carbon atom of the alkyl group or via a        carbon atom of the aryl group;    -   substituted and unsubstituted, preferably unsubstituted        cycloalkylaryl residues wherein the cycloalkyl group is having        from 3 to 8 carbon atoms and the aryl group is having from 6 to        16 carbon atoms, in particular cyclopropyl-, cyclobutyl-,        cyclopentyl-, cyclohexyl-substituted phenyl, which        cycloalkylaryl residues may be linked to the basic structure of        the thioamino acid (A) of the general formula I via a carbon        atom of the cycloalkyl group or via a carbon atom of the aryl        group;    -   substituted and unsubstituted, preferably unsubstituted        heteroaryl residues having at least one hetero atom selected        from the group consisting of oxygen, sulfur, nitrogen and        phosphorus atoms, in particular residues derived from furane,        xanthene, thiophene, pyrrole, imidazole, triazoles, tetrazole,        pyridine, pyridazine, pyrimidine, pyrazene, triazines,        tetrazines, indole, quinoline, isoquinoline, purine or        phosphinine;    -   substituted and unsubstituted, preferably unsubstituted        alkylheteroaryl residues wherein the alkyl group is having from        1 to 4 carbon atoms, in particular the alkyl groups described        hereinbefore, and the heteroaryl group is having at least one        hetero atom selected from the group consisting of oxygen,        sulfur, nitrogen and phosphorus atoms, in particular the        heteroaryl groups as described hereinbefore, which        alkylheteroaryl residues may be linked to the basic structure of        the thioamino acid (A) via a carbon atom of the alkyl group or        via a carbon atom of the heteroaryl group;    -   substituted and unsubstituted, preferably unsubstituted        cycloalkylheteroaryl residues wherein the cycloalkyl group is        having from 3 to 8 carbon atoms, in particular the cycloalkyl        groups as described hereinbefore, and the heteroaryl group is        having at least one hetero atom selected from the group        consisting of oxygen, sulfur, nitrogen and phosphorus atoms, in        particular the heteroaryl groups as described herein before; and    -   substituted and unsubstituted, preferably unsubstituted        arylheteroaryl residues wherein the aryl group is having from 6        to 16 carbon atoms, in particular the aryl groups as described        hereinbefore, and the heteroaryl group is having at least one        hetero atom selected from the group consisting of oxygen,        sulfur, nitrogen and phosphorus atoms, in particular the        heteroaryl groups as described herein before.

Alternatively, the residues R¹ and R2 together form a saturated orunsaturated, preferably saturated, substituted or unsubstituted,preferably unsubstituted ring having 3 to 6 carbon atoms, wherein nocarbon atom or 1 or 2 carbon atoms is or are replaced by one hetero atomselected from the group consisting of oxygen, sulfur, nitrogen andphosphorus atoms.

The residue R³ of the general formula I is a single residue R¹ or R² ora covalent bond or bivalent group linking the carbon atom carrying theamino group and the carboxyl group to one of the residues R¹ or R² or tothe ring formed by the residues R¹ and R². The bivalent linking group isstable in the presence of the quaternary ammonium salt (B), which meansthat it does not hydrolyze or hydrolyzes only very slowly to a verysmall extent so that the concentration of the hydrolyzation products isso low that they do not interfere with the function of the compositionsof the invention.

Preferably, the bivalent linking group is selected from the groupconsisting of:

-   —O—, —C(O)—, —C(S)—, —C(O)—O—, —O—C(O)—O—, —O—C(S)—O—;-   —NR¹—, =N—, —N=N—, —NR¹—C(O)—, —NR¹—NR¹—C(O)—, —NR¹—NR¹—C(S)—,    —O—C(O)—NR¹—,-   —O—C(S)—NR¹—, —NR¹—C(O)—NR¹—, —NR¹—C(S)—NR¹—;-   —S—, —S(O)—, —S(O)₂—, —O—S(O)₂—, and —NR¹—S(O)₂—,    wherein the residue R¹ is having the above-described meaning.

Generally, the substituted residues R¹, R² and R³ described above cancontain any substituents as long as the substituents are stable in thepresence of the quaternary ammonium hydroxide (B), which means that theydo not hydrolyze or hydrolyze only very slowly to a very small extentand do not cause any undesired reactions which could lead to thedecomposition and/or the agglomeration and/or the formation ofprecipitates in or of the compositions of the invention. Preferably, thesubstituents are selected from the group consisting of:

-   —OR¹, —C(O)—R¹, —COOR¹, —SO₃R¹, —P(O)₂R¹, —N(—R¹)₂,-   —NR¹—C(O)(—R¹)₂;-   —F, —Cl, —CN and —NO₂;    wherein the residue R¹ is having the above-described meaning.

Additional examples for thioamino acids (A) of the general formula I areknown from the international patent application WO 02/22568, page 13,line 9, to page 16, line 12.

The thioamino acids (A) of the general formula I can be racemic orenantiomeric mixtures which may be equimolar or non-equimolar, or one ofthe respective enantiomers or diastereomers.

More preferably, at least one of the residues R¹, R² and R³ describedabove is a hydrogen atom. Even more preferably, all of the residues R¹,R² and R³ are hydrogen atoms.

Therefore, most preferably, the thioamino acid (A) is selected fromcysteine and homocysteine, in particular, cysteine, especiallyL-cysteine.

The compositions of the invention comprise as the second essentialcomponent at least one, preferably one quaternary ammonium hydroxide(B). More preferably, the quaternary ammonium hydroxide (B) has thegeneral formula II:N(—R¹)₄ ⁺OH⁻  (II).

In the general formula II, the residue R¹ is having the above definedmeaning except hydrogen atom, whilst all the residues R¹ are the same orat least two residues R¹ are different from each other and all theresidues R¹ are single residues or at least two residues R¹ form asaturated or unsaturated, substituted or unsubstituted ring having 3 to6 carbon atoms, wherein no carbon atom or 1 or 2 carbon atoms arereplaced by one hetero atom selected from the group of oxygen, sulfur,nitrogen and phosphorus atoms.

More preferably, the residue R¹ of the general formula II is selectedfrom the group consisting of straight and branched, substituted andunsubstituted, saturated aliphatic residues having 1 to 10, inparticular, 1 to 4 carbon atoms.

In the case that the quaternary ammonium hydroxide (B) of the generalformula II only contains residues R¹ which are unsubstituted andsaturated, all residues R¹ are preferably the same.

In the case that the quaternary ammonium hydroxide (B) of the generalformula II contains residues R¹ which are a substituted and saturated,it is preferred that only one of the residues R¹ is substituted.

Particularly preferably, the quaternary ammonium hydroxide (B) of thegeneral formula II contains methyl, ethyl, propyl, isopropyl, n-butyl,sec-butyl, iso-butyl, tert-butyl, n-pentyl, 2-hydroxyethyl, 2- and3-hydroxypropyl and/or 4-hydroxy-n-butyl groups, in particular, methyland/or 2-hydroxyethyl groups.

Most particularly preferably, tetramethylammonium hydroxide (TMAH)and/or choline, especially TMAH, is or are used.

The compositions of the invention contain as the third essentialcomponentat least one chelating and/or corrosion inhibiting agent (C)selected from the group consisting of aliphatic and cycloaliphaticamines having at least two, preferably two primary amino groups, andaliphatic and cycloaliphatic amines having at least one, preferably onehydroxy group.

Preferably, the aliphatic amine (C) having at least two primary aminogroups is selected from the group consisting ethylenediamine,propylenediamine, n-butylenediamine, diethylenetriamine,dipropylenetriamine, di-n-butylenetriamine, triethylenetetraamine,tripropylenetetraamine, and tri-n-butylenetetraamine, more preferablyethylenediamine and diethylenetriamine, most preferably ethylenediamineor diethylenetriamine.

Preferably, the cycloaliphatic amine (C) is selected from the groupconsisting of 1,2-, 1,3-and 1,4-diamino cyclohexane;

Preferably, the aliphatic amine (C) having at least one hydroxy group isselected from the group consisting of ethanolamine, diethanolamine andtriethanolamine, most preferably ethanolamine.

Preferably, the cycloaliphatic amine (C) having at least one hydroxygroup is selected from the group consisting of 2-, 3- and 4-hydroxycyclohexylamine.

Particularly preferably, the chelating and/or corrosion inhibiting agent(C) is selected from the group consisting of ethylenediamine anddiethylenetriamine.

The compositions of the invention comprise as the fourth essentialcomponent at least one, preferably one nonionic surfactant (D) selectedfrom the group of

-   -   acetylenic alcohols, preferably acetylenic monoalcohols and        diols;    -   alkyloxylated, preferably ethoxylated, acetylenic alcohols,        preferably acetylenic monoalcohols and diols; and    -   alkyloxylated, preferably ethoxylated, sorbitan monocarboxylic        acid mono esters, preferably fatty acid mono esters.

Most preferably, the acetylenic monoalcohols and diols (D) and theirethoxylated derivatives (D) are selected from the group consisting of3,5-dimethyl-1-hexyne-3-ol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol and2,5,8,11-tetramethyl-6-dodecyne-5,8-diol, and their ethoxylatedderivatives.

More preferably, the ethoxylated sorbitan fatty acid mono esters (D) areselected from the group consisting of ethoxylated sorbitan fatty acidmono esters having 20 to 100, most preferably 20 to 80 ethoxy groups tothe molecule. More preferably, the fatty acid residues are selected fromthe group consisting of fatty acid residues having 10 to 20 carbonatoms. Most preferably, the fatty acid residues are selected from thegroup consisting of laurate, palmitate, stearate and oleate.

Optionally, the compositions of the invention can contain at least onefunctional additive (E) which is different from the essential components(A), (B), (C) and (D). Preferably, the functional additive (E) isselected from the group consisting of corrosion inhibitors, bases,complexing or chelating agents, film forming agents, surfactants andpH-adjusting agents.

Preferably, the complexing or chelating, film-forming and/or corrosioninhibiting agent (E) is selected from the group consisting of aromaticcompounds having at least one, preferably one acid group, in particularat least one, preferably one carboxylic acid group, and at least one,preferably one hydroxy group, and nitrogen containing cyclic compounds.

More preferably, the aromatic compound (C) having at least one,preferably one carboxylic acid group and at least one, preferably onehydroxy group is selected from the group consisting of salicylic acid,3- and 4-hydroxy phthalic acid, 2-hydroxy terephthalic acid, and 3-, 4-,5- and 6-hydroxysalicylic acid, most preferably salicylic acid.

More preferably, the nitrogen containing cyclic compound (E) is selectedfrom the group consisting of imidazole, triazole, benzotriazole,benzimidazole and benzothiadiazole and their derivatives with hydroxy,amino, imino, carboxy, mercapto, nitro and alkyl substituents, inparticular 1,2,4-triazole.

More preferably, the surfactants (E) are selected from the groupconsisting of customary and known nonionic, and ionic, cationic andamphoteric surfactants as described, for example, in the Americanpatents U.S. Pat. No. 6,465,403 B1, column 8, lines 17 to 65.

More preferably, the base (E) is ammonia.

More preferably, the pH-adjusting agent (E) is selected from the groupof aliphatic carboxylic acids, preferably formic acid, acetic acid,propionic acid, lactic acid, tartaric acid and citric acid.

The compositions of the invention can contain the essential components(A), (B), (C) and (D) and optionally (E) in broadly varying amounts.Thus, the compositions of the invention can be highly concentratedsolutions which contain only small amounts of water.

Preferably, the compositions of the invention are diluted or highlydiluted aqueous compositions, i.e., they contain more than 50% byweight, more preferably more than 75% by weight and, most preferably,more than 90% by weight of water, each weight percentage being based ona complete weight of a composition of the invention.

The concentration of the thioamino acid (A) in the composition of theinvention can vary broadly and, therefore, can be adjusted mostadvantageously to the requirements of the particular composition of theinvention and method of the invention. Preferably, the composition ofthe invention contains, based on the complete weight of the composition,0.1 to 20% by weight, more preferably 0.1 to 15% by weight and, mostpreferably, 0.1 to 10% by weight of the thioamino acid (A).

Likewise, the concentration of the quaternary ammonium hydroxide (B) inthe composition of the invention can vary broadly and, therefore, can beadjusted most advantageously to the requirements of a particularcomposition of the invention and method of the invention. Preferably,the composition of the invention contains, based on the complete weightof the composition, 0.1 to 20% by weight, more preferably 0.1 to 15% byweight and, most preferably, 0.1 to 10% by weight of the quaternaryammonium hydroxide (B).

Moreover, the concentration of the chelating and/or corrosion inhibitingagent (C) in the composition of the invention can vary broadly and,therefore, can be adjusted most advantageously to the requirements of aparticular composition of the invention and method of the invention.Preferably, the composition of the invention contains, based on 10 thecomplete weight of the composition, 0.05 to 15% by weight, morepreferably 0.1 to 12.5% by weight and, most preferably, 0.1 to 10% byweight of the chelating and/or corrosion inhibiting agent (C).

Also the concentration of the nonionic surfactant (D) in the compositionof the invention can vary broadly and, therefore, can be adjusted mostadvantageously to the requirements of a particular composition of theinvention and method of the invention. Preferably, the composition ofthe invention contains, based on the complete weight of the composition,0.001 to 5% by weight, preferably 0.005 to 4% by weight and mostpreferably as 0.01 to 3% by weight of the nonionic surfactant (D).

Also the concentration of the at least one functional additive (E) canvary broadly and, therefore, can be adjusted most advantageously to therequirements of a composition of the invention and method of theinvention. Most preferably, the at least one functional additive (E) isused in the effective concentrations customary and known to the skilledartisan.

The compositions of the invention can be prepared by customary andstandard mixing processes and mixing apparatuses such as agitatedvessels, in-line dissolvers, high shear impellers, ultrasonic mixers,homogenizer nozzles or counterflow mixers, can be used for carrying outthe mixing of the components of the compositions in the desired amounts.

The compositions of the invention are excellently suited for the methodsof the invention.

Moreover, the compositions of the invention are also excellently suitedfor cleaning all kinds of processing tools such as polishing pads,sensors, nozzles, pipes and/or structural features of the equipmentused, which tools come into contact with other processing liquids usedin fabricating electrical or optical devices.

The main purpose of the methods of the invention however is theprocessing of substrates useful for fabricating electrical devices, inparticular, semiconductor integrated circuits

(ICs); liquid crystal panels; organic electroluminescent panels; printedcircuit boards; micro machines; DNA chips; micro plants and magneticheads; more preferably ICs with LSI (large-scale integration) or VLSI(very-large-scale integration); as well as optical devices, inparticular, optical glasses such as photo-masks, lenses and prisms;inorganic electro-conductive films such as indium tin oxide (ITO);optical integrated circuits; optical switching elements; opticalwaveguides; optical monocrystals such as the end faces of optical fibersand scintillators; solid laser monocrystals; sapphire substrates forblue laser LEDs; semiconductor monocrystals; and glass substrates formagnetic disks.

It is essential that the methods of the invention make use of at leastone composition of the invention in at least one process step.

Preferably, the methods of the invention involve surface preparation,pre-plaiting cleaning, post-etch cleaning and/or post-CMP cleaningsteps, in particular post-CMP cleaning steps.

The methods of the invention are particularly well-suited for theprocessing of substrates useful for fabricating ICs with LSI or VLSI, inparticular in the back end of the line processing (BEOL).

The methods of the invention are most particularly well-suited for thepost-CMP cleaning of semiconductor wafers in the fabrication of ICs withLSI or VLSI, in particular by the copper damascene or dual damasceneprocess.

As is known in the art, a typical equipment for the CMP consists of arotating platen which is covered with a polishing pad. The wafer ismounted on a carrier or chuck with its upper side down facing thepolishing pad. The carrier secures the wafer in the horizontal position.This particular arrangement of polishing and holding device is alsoknown as the hard-platen design. The carrier may retain a carrier padwhich lies between the retaining surface of the carrier and the surfaceof the wafer which is not being polished. This pad can operate as acushion for the wafer.

Below the carrier, the larger diameter platen is also generallyhorizontally positioned and presents a surface parallel to that of thewafer to be polished. Its polishing pad contacts the wafer surfaceduring the planarization process. During the CMP process of theinvention, the CMP agent (A), in particular, the CMP agent of theinvention is applied onto the polishing pad as a continuous stream or indropwise fashion.

Both the carrier and the platen are caused to rotate around theirrespective shafts extending perpendicular from the carrier and theplaten. The rotating carrier shaft may remain fixed in position relativeto the rotating platen or may oscillate horizontally relative to theplaten. The direction of rotation of the carrier typically, though notnecessarily, is the same as that of the platen. The speeds of rotationfor the carrier and the platen are generally, though not necessarily,set at different values.

Customarily, the temperature of the platen is set at temperaturesbetween 10 and 70° C.

For further details reference is made to the international patentapplication WO 2004/063301 A1, in particular page 16, paragraph [0036]to page 18, paragraph [0040] in conjunction with the FIG. 1.

After the CMP step, the surface of the semiconductor wafer is contactedwith a composition of the invention for a time and a temperaturesufficient to clean the unwanted contaminants and residues from thesubstrate surface. Optionally, the substrate is rinsed to remove thecomposition of the invention and the contaminants and residues and driedto remove any excess solvents or rinsing agents.

Preferably, the methods of the invention use a bath or a sprayapplication to expose the substrate to the composition. Bath or spraycleaning times are generally one minute to 30 minutes, preferably 5minutes to 20 minutes. Bath or spray cleaning temperatures are generally10° C. to 90° C., preferably 20° C. to 50° C. However, megasonics andultrasonic, preferably megasonics cleaning methods can also be applied.

If required, the rinse times are generally 10 seconds to 5 minutes atroom temperature, preferably 30 seconds to 2 minutes at roomtemperature. Preferably, deionized water is used to rinse thesubstrates.

If required, the drying of the substrates substrates can be accomplishedusing any combination of air-evaporation, heat, spinning or pressurizedgas. The preferred drying technique is spinning under a filtered inertgas flow, such as nitrogen, for a period of time until the substrate isdry.

EXAMPLES Examples 1 to 4

The Preparation of Aqueous Alkaline Cleaning Compositions ContainingL-Cysteine

The aqueous alkaline cleaning compositions of the examples 1 to 4 wereprepared by mixing their ingredients and homogenizing the resultingmixtures. The Table 1 summarizes their compositions.

TABLE 1 The Compositions of the Aqueous Alkaline Cleaning Compositions(Balance: Water) TMAH^(a))/ DETA^(b))/ Cysteine/ Film- pH - % % %Surfac- forming adjusting Example by weight by weight by weight tantAgent^(e)) agent^(f)) 1 10 7 8 0.2^(c)) 2 1.5 2 0.5 0.35 0.4 0.01^(c))0.1 0.07 3 10 7 8 0.2^(d)) 2 1.5 4 0.5 0.35 0.4 0.01^(d)) 0.1 0.07^(a))tetramethylammonium hydroxide; ^(b))diethylenetriamine;^(c))3,5-dimethyl-1-hexyn-3-ol; ^(d))polyoxyethylene sorbitan laurate;^(e))1,2,4-triazole; ^(f))citric acid.

The concentrated compositions of the examples 1 and 3 were stable uponprolonged storage when air was excluded. Therefore, they could be mostadvantageously manufactured, stored, handled and shipped. Thus, it waspossible to deliver the concentrated compositions most economically tothe customer who could easily dilute them before use.

The diluted compositions of the examples 2 and 4 were likewise stableeven upon comparatively long exposure to oxygen and exhibited aparticularly high cleaning efficacy with only a very small change of thesurface roughness during the cleaning of copper surfaces.

Compositions containing ethylenediamine instead of diethylenetriamineexhibited the same advantageous properties and effects.

Examples 5 to 6

The Etching Rates of the Aqueous Alkaline Compositions of the Examples 2and 4

The composition of the example 2 was used for the example 5 and thecomposition of the example 4 was used for the example 6.

The etching rates were measured by the 4-point probe (Napson) method andconfirmed by the atomic force microscopy (AFM).

To this end, pieces of electroless copper deposit (ECD) wafers wereimmersed in the various aqueous alkaline cleaning compositions at roomtemperature for 1 hour (4-point probe measurements) or 1 minute (AFMmeasurements). Thereafter, the ECD wafers were taken from thecompositions, rinsed with water and dried in a nitrogen stream at roomtemperature. The ECD wafers of the examples 5 and 6 were not etched andshowed no change in their surface roughness.

Compositions containing ethylenediamine instead of diethylenetriamineexhibited the same advantageous properties and effects.

Examples 7 and 8 and Comparative Experiment C1

The Cleaning Efficacy of the Aqueous Alkaline Cleaning Compositions ofthe Examples 2 and 4 (Examples 7 and 8) in Comparison with DeionizedWater (Comparative Experiment

C1)

The composition of the example 2 was used for the example 7; and thecomposition of the example 4 was used for the example 8. Deionized waterwas used for the comparative experiment C1.

The cleaning efficacy of the aqueous alkaline cleaning compositions wastested as follows. ECD copper wafer pieces were contaminated with CMPagents containing silica particles having a mean primary particlediameter of 30 nm as measured with the laser light scattering method.Thereafter, the contaminated ECD copper wafer pieces were treated withthe compositions of the example 2 or 4 and, for purposes of comparison,with deionized water for one minute each. Thereafter, the surfaces ofthe treated ECD copper wafer pieces were checked for particle residuesby scanning electron microscopy (SEM). Whereas the surfaces of the ECDcopper wafer pieces treated with the compositions of the examples 2 and4 were free from silica particles, the surfaces of the ECD copper waferpieces treated with deionized water were still covered with considerableamounts of silica particles.

Compositions containing ethylenediamine instead of diethylenetriamineexhibited the same advantageous properties and effects.

The invention claimed is:
 1. An aqueous alkaline composition free fromorganic solvents and metal ion-free silicates, wherein the compositioncomprises: (A) a thioamino acid comprising a primary amino group and amercapto group; (B) a quaternary ammonium hydroxide; (C) at least onechelating and/or corrosion inhibiting agent selected from the groupconsisting of an aliphatic amine comprising at least two primary aminogroups, a cycloaliphatic amine comprising at least two primary aminogroups, an aliphatic amine comprising a hydroxyl group, and acycloaliphatic amine comprising a hydroxy group; and (D) at least onenonionic surfactant selected from the group consisting of an acetylenicalcohol, an alkyloxylated acetylenic alcohol, and an alkyloxylatedsorbitan monocarboxylic acid mono ester.
 2. The aqueous alkalinecomposition of claim 1, wherein the thioamino acid (A) has formula (I):HS—[—C(—R¹)(—R²)—]_(n)—C(—R³)(—NH₂)—COOH  (I), wherein: n is an integerof from 1 to 3; R¹ and R² are each independently selected from the groupconsisting of a hydrogen atom; a straight or branched, saturated orunsaturated, substituted or unsubstituted aliphatic residue comprisingfrom 1 to 10 carbon atoms; a substituted or unsubstituted, saturated orunsaturated cycloalkyl residue comprising from 3 to 8 carbon atoms; asubstituted or unsubstituted, saturated or unsaturated alkylcycloalkylresidue, wherein the alkyl groups comprise from 1 to 4 carbon atoms andthe cycloalkyl group comprises from 3 to 8 carbon atoms; a substitutedor unsubstituted aryl residue comprising from 6 to 16 carbon atoms; asubstituted or unsubstituted alkylaryl residue, wherein the alkyl groupcomprises from 1 to 4 carbon atoms and the aryl group comprises from 6to 16 carbon atoms; a substituted or unsubstituted cycloalkylarylresidue, wherein the cycloalkyl group comprises from 3 to 8 carbon atomsand the aryl group comprises from 6 to 16 carbon atoms; a substituted orunsubstituted heteroaryl residue comprising at least one hetero atomselected from the group consisting of oxygen, sulfur, nitrogen, andphosphorus; a substituted and unsubstituted alkylheteroaryl residue,wherein the alkyl group comprises from 1 to 4 carbon atoms and theheteroaryl group comprises at least one hetero atom selected from thegroup consisting of oxygen, sulfur, nitrogen, and phosphorus; asubstituted or unsubstituted cycloalkylheteroaryl residue, wherein thecycloalkyl group comprises from 3 to 8 carbon atoms and the heteroarylgroup comprises at least one hetero atom selected from the groupconsisting of oxygen, sulfur, nitrogen, and phosphorus; and asubstituted or unsubstituted arylheteroaryl residue, wherein the arylgroups comprise from 6 to 16 carbon atoms and the heteroaryl groupcomprises at least one hetero atom selected from the group consisting ofoxygen, sulfur, nitrogen, and phosphorus; or, alternatively, R¹ and R²together forming form a saturated or unsaturated, substituted orunsubstituted ring comprising from 3 to 6 carbon atoms, wherein at most2 carbon atoms are replaced by a hetero atom selected from the groupconsisting of oxygen, sulfur, nitrogen, and phosphorus; and R³ is asingle residue R¹ or R², a covalent bond, or a bivalent group linkingthe carbon atom carrying the amino group and the carboxyl group to oneof the residues R¹ or R² or to the ring formed by the residues R¹ andR².
 3. The aqueous alkaline composition of claim 2, wherein thethioamino acid (A) is a racemic mixture, an enantiomeric mixture, or oneof enantiomers or diastereomers thereof.
 4. The aqueous alkalinecomposition of claim 3, wherein at least one of the residues R¹, R², andR³ is a hydrogen atom.
 5. The aqueous alkaline composition of claim 4,wherein all of the residues R¹, R², and R³ of the thioamino acid (A) arehydrogen atoms.
 6. The aqueous alkaline composition of claim 5, whereinthe thioamino acid (A) is L-cysteine.
 7. The aqueous alkalinecomposition of claim 2, wherein the quaternary ammonium hydroxide (B)has formula (II):N(—R¹)₄ ^(+OH) ⁻  (II), wherein the residue R¹ has the same meaning asin formula (I), except the hydrogen atom, whilst all the residues R¹ arethe same or at least two residues R¹ are different from each other, andall the residues R¹ are single residues or at least two residues R¹ forma saturated or unsaturated, substituted or unsubstituted ring comprisingfrom 3 to 6 carbon atoms, wherein at most 2 carbon atoms are replaced bya hetero atom selected from the group consisting of oxygen, sulfur,nitrogen, and phosphorus.
 8. The aqueous alkaline composition of claim7, wherein, in formula (II), the residue R¹ is methyl.
 9. The aqueousalkaline composition of claim 1, wherein: the aliphatic amine (C)comprising at least two primary amino groups are selected from the groupconsisting of ethylenediamine, propylenediamine, n-butylenediamine,diethylenetriamine, dipropylenetriamine, di-n-butylenetriamine,triethylenetetraamine, tripropylenetetraamine, andtri-n-butylenetetraamine; the cycloaliphatic amine (C) comprising atleast two primary amino groups are selected from the group consisting of1,2-diamino cyclohexane, 1,3-diamino cyclohexane, and 1,4-diaminocyclohexane; the aliphatic amine (C) comprising at least one hydroxygroup is selected from the group consisting of ethanolamine,diethanolamine and triethanolamine; and the cycloaliphatic amine (C)comprising at least one hydroxy group is selected from the groupconsisting of 2-hydroxy cyclohexylamine, 3-hydroxy cyclohexylamine, and4-hydroxy cyclohexylamine.
 10. The aqueous alkaline composition of claim1, wherein the nonionic surfactant (D) is selected from the groupconsisting of an acetylenic monoalcohol, an acetylenic diol, analkyloxylated acetylenic monoalcohol, an alkyloxylated acetylenic diol,and an alkyloxylated sorbitan monocarboxylic acid fatty acid mono ester.11. The aqueous alkaline composition of claim 1, further comprising: afunctional additive (E), which is different from the components (A),(B), (C), and (D).
 12. The aqueous alkaline composition of claim 11,wherein the functional additive (E) is selected from the groupconsisting of a corrosion inhibitor, a base, a complexing or chelatingagent, a film forming agent, a surfactant, and a pH-adjusting agent. 13.A method for processing an electrical or optical device substrate, themethod comprising: contacting a substrate surface with the aqueousalkaline composition of claim
 1. 14. The method of claim 13, wherein theprocessing is a surface preparation, pre-plaiting cleaning, post-etch,or post-chemical polishing cleaning.
 15. The method of claim 13, whereinthe electrical device substrate is a semiconductor integrated circuit(IC); a liquid crystal panel; an organic electroluminescent panel; aprinted circuit board; a micro machine; a DNA chip; a micro plant, or amagnetic head substrate.
 16. The aqueous alkaline composition of claim1, wherein the thioamino acid (A) is cysteine or homocysteine.
 17. Theaqueous alkaline composition of claim 7, wherein, in formula (II), eachR¹ in the quaternary ammonium hydroxide (B) is independently methyl,ethyl, propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, tert-butyl,n-pentyl, 2hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, or4-hydroxy-n-butyl group.
 18. The method of claim 13, wherein the opticaldevice substrate is an optical glass, an inorganic electro-conductivefilm, an optical integrated circuit, an optical switching element, anoptical waveguide, an optical monocrystal, a solid laser monocrystal, ablue laser LED sapphire substrate, a semiconductor monocrystal, and amagnet disk glass substrate.